Gamma rays are a type of electromagnetic radiation, like X-rays and visible light, but with much higher energy. They are emitted by radioactive elements and can also be produced by nuclear reactions.

Gamma rays are extremely penetrating and can pass through most materials, including paper. However, the amount of gamma radiation that is transmitted through a material depends on the thickness and density of the material, as well as the energy of the gamma rays.

For example, a sheet of paper will block a significant amount of low-energy gamma rays, but it will only slightly attenuate high-energy gamma rays. This is because low-energy gamma rays are more likely to interact with the atoms in the paper, while high-energy gamma rays are more likely to pass through them without interacting.

In general, the more dense a material is, the more effectively it will block gamma radiation. This is why lead is often used as a shielding material for gamma rays, as it is a very dense metal.